


Experimental

by Che_Butter



Category: Adventure Time
Genre: (Non-consensual/Consensual Bondage, 3 way, Anal & Traditional Sex, Blindfolds, COMPLETED STORY!!, Chloroform, Collars/Leashes, Eating out, Explicit Language, F/F, F/M, Face-Sitting, Finn Mertens (SUB/DOM), Hair-pulling, Kidnapping, Marceline The Vampire Queen (SUB/DOM), Massage, Masturbation, Multi, Pregnancy, Princess Bubblegum (SUB/DOM), Rape, Repeated Orgasms, Sadistic Torture, Sleep Groping, Stretcher, Vibrator, Whipping, suffocation
Language: English
Status: Completed
Published: 2019-06-15
Updated: 2019-06-18
Packaged: 2020-05-12 10:55:48
Rating: Mature
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 4
Words: 13,473
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19227757
Author URL: https://archiveofourown.org/users/Che_Butter/pseuds/Che_Butter
Summary: Finn is unaware that his best friends, Princess Bubblegum and Marceline the Vampire Queen are planning a rather erotic surprise for his 18th birthday.But his long term friends are DEFINITELY unaware of how far the just recently turned adult human male is going to go to get his sexual revenge.Much to both girls secret delight.





	1. Cumming Of Age

**Author's Note:**

> Hello everybody here on AO3!!
> 
> Chè_Butter (Pronounced: Shay_Butter) here! This is my very first adult themed Adventure Time fan-fiction posted here on Archive of Our Own. This writing was originally posted for a time on FanFiction.net, but while it got some views, it never really picked up a lot of attention. Hence, why I am posting it here. 
> 
> Enjoy!!

**Summary for the Chapter:**

> Finn Mertens turns 18 years old and ends up getting captured by a very horny Princess Bubblegum and Marceline the Vampire Queen, who wish to celebrate Finn’s birthday in a very intimate way.

This wasn’t how he expected to spend his 18th birthday. Yet somehow Finn Mertens found himself bound, gagged and blindfolded, laying on a rather cool surface. He flexed his muscles subconsciously as he tried to situate himself in a more comfortable position. It wasn’t any use. The young man could flex all he wanted but the tight, coarse ropes that were wrapped around his wrists and chest prevented any escape. Whoever had kidnapped him had ensured that their victim would be denied any sort of movement.

Finn squirmed in discomfort at the memory of his capture. He had been walking to The Candy Kingdom at a rather brisk pace. After receiving word that Princess Bubblegum was in desperate need of assistance with an experiment gone wrong, he had wasted no time in rushing to her aid. Well, that was until he got grabbed. The young man had just started to see The Candy Castle when he felt a hand snake around his waist, pinning his flailing arms to their sides. Finn had tried to kick and trip his attacker, but his panicked methods were unsuccessful. Especially when another hand covered his mouth, silencing his curses and forcing the hero to breathe in a sickeningly sweet scent.

It happened so quickly after that almost heart stopping moment. Finn found himself unable to keep his eyes open. The hero had tried to hold his breath. Anything to keep himself alert. But the more he had mentally and physically fought against his captor, the more dizzy and weaker he felt. Until eventually, he saw only darkness. Which he still was seeing. Thanks to the blindfold knotted tightly around his head. Again, this was not how Finn wanted to spend his birthday. Not in the slightest. His muffled sigh echoed around him. Blast his luck. Blast it all.

The human's long blonde hair flowed down his bare chest. Odd, that his captors had undressed him partially. He was grateful that only his shirt was missing. Like really grateful. Maybe rape was off the table. He inwardly laughed at his horrible pun considering that Finn himself was probably on a table. Another thing that might make his predicament a little bit more bearable was the simple fact that he really didn’t have to worry about overheating and sweating everywhere. The room he was in was just right in temperature. Probably if he had his iconic blue shirt on, he actually might have been too warm.

Finn tried to roll over, just like all his other attempts, he was unsuccessful. With his ankles tied in the same fashion, he was pretty much at his captor’s mercy. He sighed again. Growing more annoyed at the second. The cold metal underneath him was unforgiving as he tried to still his physical movements. He was contemplating just playing dead. Silently uttering a prayer to Glob that the person who kidnapped him would be stupid enough to fall for his terrible acting skills and release him.

That was until a door squeaked behind him. Finn tried to stay still but only ending up thrashing more when he heard footsteps. They were dainty sounding. Like a lady’s footsteps. Weird.

“My goodness Finn! Aren’t you just a sight to behold!” A seductive voice said. Yep. Definitely a woman’s. He heard the door squeak again. Finn once again tried to squirm. He felt delicate, soft hands tracing his wriggling form. “How beautiful, you are.” Her sweet breath tickled his ear. He knew that voice! But it couldn’t be! 

His captor didn’t hesitate to touch his muscles, causing Finn to involuntarily groan. Her laughter was the only thing that made him stop. The human’s mind was a blur trying to decipher who his kidnapper was and the growing pressure in his groin.

Right on que, The female’s fingers somehow found themselves at Finn’s belt loop. The human felt her slowly unzipping his pants. Against his will, Finn found himself with his blue shorts down at his ankles. He struggled with the realization that he was now only clothed in his boxers. Oh Glob! So much for thinking that he wasn’t going to get raped! The hero tried to buck the prying fingers off his nether regions, but quickly stopped when they clutched his member.

“I wouldn’t do that if I were you, Finn.” The voice purred. “You really would be missing out.”

Finn forced himself to still his body movements. It was difficult not to fight back. He was feeling a mixture of fear and lust. The latter being rather shocking to the hero. Since when was he afraid? The last time he was really scared like this, was when he had a massive fear of water and that was years ago!  


“Hmm, since you listened to me. How about a reward?” The voice teased. His reward was yet another laugh. It was a very amused laugh. A rather attractive laugh that shamefully aroused Finn greatly, which under his captor’s hand, only caused his penis to grow and twitch more and more with its un-denying approval. Finn’s cheeks burned with the instant reaction.

“Is someone enjoying his predicament?” The voice said taunted. Finn panted as the woman began fondling his still underwear protected dick. He couldn’t control his body’s excitement as the invading fingers softly stroked his penis. The cotton of his underwear rubbing against his shaft made the human dizzy. His figure bucked with the motion. Secretly enjoying the sensation that his captor was creating. 

“Well then how about we add some danger, my hero?” The voice whispered tauntingly. She stopped touching him. The human cried out with the loss of her touch. He struggled desperately to save the embarrassing build up that he had felt. He whimpered much to his abductor’s pleasure. It wasn’t fair.  


He heard footsteps once more, this time though circling his figure. Almost like how Finn would picture a predator stalking its prey. Her footsteps didn’t sound as dainty either. They sounded more heavier. Finn was starting to think that he was in fact prey. Here he was bound and completely at this woman’s mercy. He couldn’t do anything. He was helpless much to his displeasure and ironically, his pleasure.

“You know Finn, I have waited so long to finally have you like this.”

The hands were back. This time slowly gripping his waist. He felt himself lifted up on the cold table, so that he was in a sitting position. Finn tried once again to loosen the knots that held him fast. His struggling almost caused him to fall back onto the table, but the hands somehow kept him steady. This was torture! Gently the woman stroked his face. It was so soft. Finn found himself resting his head in her palm. Her fingertips played with his some of his waist length blonde hair. He moaned in contentment. Lost in her touch. 

“So long to finally have you my age.” 

Light shined in Finn’s face, blinding him temporarily. He was indeed on a medal table in a small room. Just like he predicted. But his captor was none other than, Princess Bubblegum. He had had some suspicions but he never thought they could be accurate! The sickening sweet smell smelled a lot like one of the chemicals Finn had run into many years ago when exploring PB’s lab and then there was the voice. He should have guessed it was Bubblegum. But why? He had so many questions to ask! But while his eyes were free to view the near nude candy princess, his mouth was still inaccessible. Confusion lined his handsome features.

“Oh Finn, and it's not just me, whose been waiting.” Bubblegum said her fingers forcing her hero to look at her. Her smirk made him shudder. But not as much as the busty vampire that suddenly appeared beside the princess.

“S’up Finn?” Marceline the vampire queen said. Her crooked smile showing Finn her sharp predator teeth. She was looking at him in a way that both unnerved and excited him. Then again that was nothing new. The fair skinned beauty always seemed to have that effect on people. Finn wasn’t really different. Even though the two were really good friends. Just one of the many perks of being an undead, “scary,” immortal being. 

The two girls watched Finn’s reactions. What was he thinking? Those deep blue eyes still held a puzzled gaze to them. The delicious human in front of them still struggled against his restraints, much to Marceline’s delight, but it seemed less desperate. Was he giving up? Finn definitely did look tired under closer observation. No matter. He would enjoy this.

“Ready to start the experiment, Marcy?” PB asked. Her tongue licking her pale pink lips as her eyes ravished Finn. No longer a boy. But a beautiful man. The princess noticed a small amount of drool leaking from Finn’s makeshift gag.

The vampire queen said nothing as she pulled Finn’s underwear down. Exposing his true length. Which was rather large compared to most guys that the queen had fooled around with. She stroked his pulsing member, making the hero spasm. Moans of pleasure echoed around the room. The hero’s eyes closed in ecstasy as Marceline took Finn in. Her mouth sucked the man’s genitalia with expert care. PB watched with fascination as Finn started to buck. Moans were coming from both individuals.

The bubblegum princess couldn’t help herself. It was so hot. Seeing and hearing all that was happening around her. Her fingers found her swollen clit easily. Her body started to build its own pleasure as she rubbed. She felt Finn’s eyes on her as she touched herself repeatedly. Her moans picking up tempo, but not enough to stimulate her for very long.

With Finn’s dick still in the vampire’s warm mouth, Princess Bubblegum jumped onto Finn’s other head. Ripping off his gag to French kiss him. Her hands graced his bound body, as they both battled for dominance. The princess won easily. Finn thrashed against his bonds. This time though not to break free, but to assist in the female’s endeavors. Of course, like earlier his attempts were futile. 

“Please, PB...untie me.” Finn whimpered between kisses. His eyes pleading. Begging. Longing. 

“Sorry Finn.” The princess huffed. “You have saved us many times…”

“It's our turn to save you.” The vampire finished quickly, Finn’s pre-cum evident on her ruby red mouth. 

Her eyes flashed deviously at Finn before she gently starting kissing Finn’s tip. The queen was pleased to see the human’s eyes roll back. She started licking his shaft. Just like the lollipops she would suck on when she was a kid. If her and PB’s love hostage could scream out he probably would. But The candy ruler had once more started attacking his lips with rapid fire kissing.

Finn was twitching. He was close to release. Way to close. Marceline quickly stopped licking and went to stroking. Gently and slowly. Finn’s eyes looked down at Marcy’s. What she saw was almost enough to get her to get him to climax. Almost enough. The vampire was having too much fun. Marceline's slitted eyes that she showed back up to her prisoner only showed her immense amusement at the man’s predicament. 

“Please, just finish me off.” Finn pleaded as Bubblegum started nibbling his ears. His body shaking with a climax that he just couldn’t seem to reach. He begged and pleaded. His mouth was free for the time being. Why not ask? But like his request to be untied, it fell on deaf ears. 

Between Princess Bubblegum’s gentle nibbling and kissing, and Marceline’s forceful strokes, scratches and blowjobs, he was truly helpless to the pleasure he was receiving. He wanted to help. When Bonnibel once more started kissing his lips, he made the first move. And his last one too.

PB quickly retired his gag, silencing him once more after he tried to dominate the situation. A frustrated moan was the only thing heard after that.

“I think he’s ready PB.” Marceline said with a smirk. “I am going in.” She didn’t wait for Bonnie’s permission or really for Bonnie to get out of the way. The vampire effortless pushed Finn back onto the table. He squirmed a bit, as she sat on top of him. The table was cold. The human attempted to shake the gag off, stopping only with a wild look in his eyes when he felt Marceline gripping his penis in a vice like grip. It hurt. But Finn was a sadist individual anyway, so it was kinda enjoyable.

“Ready or not here I come.” Marcy yelled gleefully. Sitting her perfect hourglass figure on Finn’s awaiting dick. She was smooth and slick. Warmth flooded Finn’s body, as pressure built up around the two. Marceline had obviously had sex before as her vaginal insides weren’t tight at all. It didn’t surprise The human though. It was kinda a known fact that the vampire queen got around. With each grind that the immortal initiated, Finn felt himself edging closer and closer. His eyebrows furrowed together in concentration. The climax building and building. Marceline started drooling, her body acting animalistic as she herself grew closer to orgasm.

The candy princess couldn’t resist the temptation. She herself once more ripped the gag off of the trussed up adult. Her eyes meeting Finn’s momentarily. “Eat me out, Finn!” Bonnie demanded. She Jumped onto Finn’s face, her ass swallowing her knight in the process. The princess’s vagina though lined up perfectly with the hero’s mouth. She instantly felt Finn’s moist tongue licking her most intimate part. She bucked with her fellow lovers, gripping Finn’s twitching arms and kissing Marceline's lips. Bubblegum’s nails dug into Finn painfully. Her candy essence stuck to his cheeks, his nose and his other facial features, making it nearly impossible to breathe. PB was such a messy girl!! Finn couldn’t imagine a better way to die. He growled as he nibbled, kissed and licked her, even entering her candy entrance with his tongue. It was so hot. Too hot.

“Fiiinnn! III’mmm going to…..” Bubblegum screamed. Her voice overlapping Marceline’s own pleasure filled screams and Finn’s muffled shouts. Bonnie came first. Her sticky taffy coated Finn’s mouth, making him twitch and spasm. His oxygen gone with his completely gummed up nostrils, caused him to thrash even more wildly. Did she knew that suffocation was actually a huge turn on for him? Finn did know that PB saw everything in the candy kingdom due to the cameras she had installed to watch her citizens. Maybe she had also installed some to watch Finn. If so, then the candy monarch knew a lot a hell of a lot more about Finn than he really wanted.

His body was at its peak. He couldn’t hold it in anymore. Finn tried to warn Marceline that he was cumming. But he was still trapped under Bubblegum’s fine ass. The surge from within his own body came. The vampire screamed out something eligible as his heat triggered hers. They both rode the waves of pleasure together. Warmth, dizziness and exhaustion overcame all three. Marceline literally fell off the table, Bonnie fell farther onto Finn. Literally centimeters away from his limp dick and Finn allowed himself to remain still. He couldn’t breathe! But he couldn’t really fight either. Might as well enjoy the feeling of true ecstasy while he could.

Bubblegum very slowly turned herself to face Finn. She smiled. Her fingers gently stroked Finn’s face, peeling off her gummy essence from his vital areas. 

“Did you have a happy birthday, Finn?” The tired princess asked. 

“Yeah, PB, I did.” Finn said. His voice still strained from swallowing all of Bonnie’s sticky cum. He was so tired. So tired and satisfied. He would plan revenge later, but for now, Finn was content with remaining both the royal’s captured prisoner.

Marceline from somewhere on the floor said something eligible again. Something that sounded like, “Don’t worry, I can’t get pregnant, I am on the pill,” came from her lips before content, deep snores came from her resting location.

“The experiment was a success then.” Bubblegum stated, allowing herself to fall back. Her eyelids slowly closing as she entered a peaceful slumber.

“I am so happy, You deserve a good fuck.”


	2. Hubba Bubba

**Summary for the Chapter:**

> Poor Princess Bubblegum. Locking herself up in her laboratory in hopes that working obsessively on her numerous science experiments will calm her increasing anxieties regarding the strange absence of her friend and hero, Finn.
> 
> The princess should know by now that not all things can be fixed with chemicals and numbers. Feelings are one of those things. Luckily for her, Finn has a massive sweet tooth. One that is craving the pretty "Hubba Bubba" herself.

**Notes for the Chapter:**

> Hey everyone!!
> 
> Heres the second chapter of The Adventure Time erotica, “Experimental” and things are really starting to heat up AGAIN. Only this time a certain blonde haired hero might change the sexual dynamics around....
> 
> Enjoy!!!

Princess Bubblegum was worried about Finn. It had been almost 2 weeks since she had seen the hero. The candy monarch was concerned. Did her and Marceline take it a bit too far? The hero had seemed to enjoy himself. I mean with all those moans, Finn HAD to be enjoying something during his predicament. People don’t just make pleasurable noises during sex if they aren’t enjoying themselves. Still though, Bonnie couldn’t shake the feeling that something was very wrong with her beloved hero.

“It’s probably just me overthinking things again.” The princess sighed as her fingers delicately grabbed the vial that contained a blue green liquid. “That’s nothing new.” She whispered to herself, tired eyes watching intently as she mixed the liquid with some of The Mother Gum in another vial. Like every other time The Mother Gum essence completely absorbed the invading liquid. 

Bubblegum didn’t even bother to record the data from her experiment. It was always the same when it came to pink liquid. Its genetic material just couldn’t be altered. Bubblegum and Neddy were all things that The Gum created. Just Bubblegum and Neddy, and try as Bubblegum might, that might just always be the case. Another sigh escaped the candy princess’s lips. She was tired and much to her displeasure, worried. She was coming to the realization more and more that no amount of science could cure her anxiety. Damn feelings!

If science wasn't the answer maybe sleep would be. Bubblegum didn't known what to do and the princess was running out of options. She let her eyelids close momentarily. A yawn escaped her pale pink lips as she allowed herself to rest on her pink arms. Her bare elbows created the perfect pillow for her nodding off figure. Bonnie was oddly comfortable. So much that she very soon after fell into a deep sleep. Unaware of the laboratory door slowly opening and closing behind the princess’s slumbering form.  
============================

His fingers trailed up and down the beautiful princess before him. Some of the slumbering princess’s long fuschia hair stuck to his pale fingers, as he stroked her cheek affectionately. Beautiful. Absolutely beautiful. 

The intruder was just starting to fondle the royal’s breasts when an angry scream echoed around the lab. Good, the princess was awake.

Another shocked scream echoed around the room as Bubblegum’s vision cleared, showing her the practically nude form of a very smug looking Finn Mertens standing over her sprawled out figure.

“Finn! What are you doing here?!” Bonnie gasped. She tried moving her hand up to conceal her completely uncovered double d’s, when she discovered that she was tied down. Her “hero” just smiled at her predicament.

The princess tested the restraints. She was tied rather tightly on her lab table that she had been using for her potion testing earlier. Bubblegum couldn’t help but feel somewhat relieved when she saw her science experiments sitting on a completely empty table top at the other end of the room. Both hands were fastened together way above her head. Her feet were tied also, only they were separated.

Under closer observation, The candy monarch noticed from her angle that two loose ends of the ropes that were holding her struggling figure still were hanging off the table. The one was containing the knots were holding her wrists and the other one being the one keeping her left leg still. 

“Finn! What is the meaning of this? I demand you let me go this instant!” 

The said hero smirked. “What’s wrong PB? Can’t get out?” He teased, slowly returning to tracing the lovely bound form.  


“That’s just too bad.” 

His low voice made Bubblegum shiver. Since when had Finn ever disobeyed an order, let alone say it in such a seductive fashion? The princess opened her mouth then closed it when Finn mouth started kissing her slender pink neck. 

“Oh my Glob.” 

Finn eyes were pleased to see how his victim arched her back as his kisses intensified. Her sighs were mostly all that were forming out of the monarch’s luscious pink lips. But occasionally Finn would be lucky and hear Bubblegum’s delighted words of satisfaction.

“Oh my Glob.”

“Oooh Finn.”

“Oh Finn. Glob Finn.”

Her voice cooed as Finn nibbled on her collarbone. Her twists were no longer as desperate to escape, they were more fueled by the princess’s need to touch the hero. Finn just laughed as she moaned. His lips found their way to the candy’s face. The soft pink body part graced Bubblegum’s cheeks, her forehead even the tip of her pointed nose. It felt wonderful. But it wasn’t what Princess Bubblegum wanted or needed. She wanted to feel his kissable lips on her own.

The princess tried to lean in to Finn’s lips, only for one of Finn’s strong hands to gently push her head back down.

“No, no, no.” The hero started. A mischievous twinkle in his blue eyes. “I wouldn’t do that princess. You would really be missing out.”

What did Finn just say to her? Rage boiled up inside the monarch in her own disbelief at Finn's words.

“How dare you?!” Bubblegum screamed in outrage when her voice returned. How dare he use her own words that she used on him a few weeks prior against her? Finn just allowed his pale body to back up away from the princess’s annoyed figure. His fingers ran their fingers down his own body as the monarch only got angrier.

“Oh PB, you don’t know how long I have dreamed of this moment.” Finn whispered slowly, his eyes closed as he hands slid down under his shorts. His cock was hard and was ready. But Bonnie needed a reminder of who was in charge. Finn allowed his hand to slowly return to his side.

“Look at what you do to me PB.” 

“What have I done to you Finn?” 

Finn was pacing around Bubblegum in a predatory way, eyeing her with a mixture of lust and desire. Yes, it made her wet. But honestly Finn’s accusation was making it harder to keep up her arousal.

“This.”

His fingers forced Bubblegum’s head to the side, so that she was looking straight at her champion’s huge bulge. If the princess moved at all, Finn’s penis would poke her eye out. Even clothed, he was massive in length. Extending far more out than any of Bubblegum’s other past flings. Glob!! The princess missed that bulge! She was practically drooling when Finn Mertens suddenly grabbed the two loose ropes ends off the table.

“But that’s not all you have done.” He said dangerously. The ruler shuddered again as she felt the ropes holding her wrists hostage pulled even tighter. Finn’s voice came from somewhere behind Bubblegum’s head. She found herself trying to locate where exactly Finn was. Her ears could hear that Finn was messing with something. But Bubblegum wasn’t quite sure what. A chair maybe? Whatever Finn was up too suddenly caused the princess’s arms to become even more straight, so that whatever slack she had possessed was nearly gone.

“You have used my love for you and by doing so, stretched me thin.”

Pain. It seared through her arms and shoulders, as Finn watched Bubblegum's body being forcibly stretched. The hero stood still for a few seconds behind his captive as she cried out. It was quite ingenious of the human to come up with the idea of the makeshift rack. The adult had tied one of the ends to Bubblegum’s many office chairs. It was quite a bit away from the monarch but could be moved closer if need be. Of course, Finn saw no need for that. Before he walked away from the source of the princess’s suffering he made sure that the chair would stay put by tying the frame to one of the laboratory floor length pillars that helped the support the area.

Bubblegum screamed out as Finn’s eyes scanned her spasming figure. Gosh, she was so pretty. Finn’s mouth quickly took one of PB’s rosy tits in his warm mouth. Her eyes closed, lost in the immense pain as her arms were stretched leaving the rest of her body sore. Yet even though the pain was driving her mad, some part of Bubblegum wanted Finn to continue. It was the animalistic side that was winning too.

“Do you like this bubbles?” Finn seductively asked. His blue eyes were dark, completely fueled by his obsession to make Bubblegum submit. The human allowed his tongue to leave a tail of saliva from the princess’s erect breasts all the way down to her navel. 

“Tell me you like this.” 

“Never.” Bubblegum said shortly. Her arms were killing her. “I will never submit to you.” 

Finn’s long hair ticked her stomach as he stood up. His eyes never leaving hers. She watched as he walked slowly around her, careful to step over the coarse rope that was stretching her arms out of socket. His fingers did though grip the slender twine as he walked by, which caused Bubblegum to wince.

“You know what else you have done?”

Finn was across from her, his heavy footsteps halting in front of another office chair. Bubblegum watched horrified as Finn started looping the rope keeping her ankles comfortable around the bottom part. The tension was slowly growing in the gum’s legs as Finn added knot after knot. By the time Finn was satisfied with his work, the princess was almost floating off the table. Her arms were on fire, but at least her legs were still somewhat comfortable.

“You have completely dominated me.”

Bubblegum’s eyes never left one of Finn’s feet, which was now resting atop the chair casually. He wouldn’t.

“Trapped me. Made me beg.”

Those cold blue eyes were back to staring in Bubblegum’s. A few drops of sweat slowly started to form on the woman's forehead.

“But not today. Not after what you and Marceline did to me. You both taught me something about myself.”

Finn absentmindedly played with a piece of his hair. 

“Taught me that I want to hear YOU beg.”

Finn’s kick sent the chair rolling down the other end of the room. Bubblegum’s left leg was pulled with it, but due to her arms being pulled the other way and her other leg being tied tightly to the table leg, she was left with her whole body being stretched in four different ways. Her screams amplified as she was pulled. Finn wasted no time in cutting the rest of Bubblegum’s dress off. The remains of the skirt fell off of her struggling form as Finn’s fingers traced overtop of the lacy black underwear.

“You tortured me.”

Bubblegum’s cries were endless. Finn only smiled when his tore the panties in two.

“You took advantage of my feelings.”

Princess Bubblegum was such a masochist. Her vagina was drenched in her own cum. Finn smirked before gazing up at his captive’s thrashing figure.

“But now, it's my turn to show you how nice it is to finally be your age.”

Finn’s tongue was warm. It's delicate touch kissed and showered the princess’s body with such gentle affection. She couldn’t refuse him, as his tongue surfed her womanhood before tipping itself into her very open entrance. The muscle kissed Bubblegum’s clitorus, enjoying when the candy sighed his name. Finn’s hand stroked her inner left thigh while the other found its way back to the woman’s breast. His calloused fingers pinched the rosy buds on one of the sloped mountains roughly.

“Why?” He asked her. Bubblegum couldn’t see him. But she could smell him. His face smelled like her. Sweet and syrupy. 

“Because you were 18.” She answered in between huffs. She couldn’t feel her arms anymore. Thank Glob, she didn’t have human type bones because they would surely be broken by now. “Because I couldn’t wait anymore.”

Now she could see him. Long, messy blonde hair and blue eyes that looked feral. So feral that they were almost scary. Marceline had always joked that Finn Mertens might be scary good when it came down to sex, but Bubblegum could never see past the adorable sweet 13 year old who was heroic and innocent in more ways than one. How wrong she was.

His nails scratched down her leg. Between being stretched like laffy taffy and then being clawed, the sensation between pleasure and pain was almost too much. 

“You couldn’t wait anymore, huh?’ 

Finn’s pants were increasing as his lips kissed along the path that his nails made. Bubblegum sighed.

“Funny. I can’t either.” 

He backed up, unbuckling his pants and let them fall to the cold ground below. His sneakers had already been disregarded sometime prior. Maybe he had taken them off sometime during Bubblegum’s nap. She wasn’t sure. Honestly though the princess was more focused on the blonde’s penis.

Her eyes widened as she closely viewed his cock. Damn, he was big! His muscular legs stepped out of his shorts and walked back over to his victim. He leaned over her until all 8 inches was right at her lips. Bubblegum blushed as the champion traced her mouth with his dick, coating it with his own bit of essence.

“Taste me princess.” He moaned out, Finn’s dick as it left the royal’s mouth left long strands that connected still to his tip. “Taste what you’ve been missing for the last 6 years.”

Bubblegum let her own tongue licked Finn’s cum off of her lips. No wonder Marceline didn’t want to share! He tasted wonderful. Delicious. Ironically like candy. Her eyes rolled back as the thick syrup covered her tongue. 

“Now feel what you have been missing.”

Finn thrusted into her then. Her body coming alive as he entered her ready entrance. She was tighter than the vampire but bigger. Finn just wrapped it up that she was gum. She would stretch to fit him. Bubblegum though did more than just that. Globs of her own gentile was sticking to Finn’s member. She was so excited that the princess was literally melting from her own body's heat. 

Bubblegum was on fire. It was building more and more in her groin and was consuming her. The pain that she was feeling in her left leg was gone replaced by the desire to orgasm. Her legs trembled as Finn thrusted harder and harder into her G-spot, making her dainty little toes curl.

“See what you have been missing?!” Finn yelled out. the princess was so hot, so fucking hot. The human could feel her pulsing as he continued reminding her of her mistake.

“See what you could have had?!”

The candy panted. Her heart was pounding in her chest. She could feel Finn the human in every cell of her body. Every nerve, every vein, every drop of candy modular screamed for Finn to finish the job.

“See how stupid you were?!”

“Finish me off Finn!” She screamed. Drool was coming out from her lips. “Prove it to me right now!” 

Finn only smirked before suddenly pulling out. She howled at the loss of contact. The pain of the Finn’s removal was far more worse than her body being stretched. She screamed.

“Please Finn!”

“Please! Please! Oh Glob! Plea….”

Finn’s hand covered Bubblegum’s quickly stopping her pleas after a few moments of hearing her desperate cries. He was staring into her very soul. What did the human adult see? Did he see that Bubblegum was truly being sincere with her words? Did Finn even care?

“Tell me right now, that you were wrong.”

Bubblegum’s eyes widened, she was about ready to bite down on Finn’s hand when he just smiled a rather menacing smile before letting her mouth go free.

“I can easily silence you like you have done to me all these years. Choose wisely.”

“I was not wrong!” Bubblegum started. Her body was trembling all over again because after she shouted out her choice of words, Finn fingers began playing with her nether regions. She tried to form more words but Finn’s movements made it more and more difficult to think.

“I…..you….I….not sorry…..oh..glob….why...help...please.” The words coming from the princess’s mouth made zero sense as Finn kept on fingering the woman’s pussy. She would clench, whenever Finn would circle around her entrance. Almost like she was trying to get him to slide in.

“Say it Bubblegum and I will finish you off.” 

The woman tried to glare at him but unknowingly only made her face show Finn more of her dire sexual need. Her body wasn’t listening anymore, it bucked against her captor’s fingers desperate for more. 

“Say you were wrong.”

“I...was…...I...no...help…..please….I...no.”

Her eyes were pleading. The heat was melting her, her curvy body was literally sticking to the table and to Finn’s fingers. Finn only demanded her to say the phrase.

“Tell me you were wrong all these years.”

Bubblegum shook her head. Deep down the princess knew she was losing the battle.

“We both know you were.” Finn whispered. His fingers leaving Bubblegum’s melting vagina to put a big glob of her into his mouth. He was blowing a pink bubble when she finally caved.

“You win Finn!!” The Monarch screamed. “You win!! I was wrong. Wrong. WRONG all these years!! You definitely were worth my time and I shouldn’t have pushed you aside! Now finish me off!!” 

“As you wish, your highness.” 

Finn thrusted himself right back into Bubblegum’s hole. Well, what was left of it. She was pretty much a glob of gum down there. 

“FINN, YEESS!! OH GLOBB! YESSS! FINN!! I AM, I AM, I AM GLOB DAMMIT CUMMING!!!”

Finn screamed out as Bubblegum’s vagina vibrated. His sperm mixed with her gum as he ejaculated. His relaxed penis slide out of the woman’s body slowly.

“Finn.” The woman whispered. She was so weak but in a good way. The said hero untied the candy’s limbs from the ropes that held her still. The ropes fell to the floor with a thud. Bubblegum was free to move but her own stickiness prevented her from bringing her hands to her sides. Her left leg though hit the table with a splat, yet neither individuals seemed to really care.

A faint blush formed around the man’s face as he began to massage his friend’s arms. She felt like a jolly rancher in some places. Her arms were one of them. He slowly worked on relieving as much pressure in her body as possible. Other than a few more content whispers of his name, Bubblegum was silent. It wasn’t long before the princess was asleep.

To which Finn kissed her head softly, climbed off the table, grabbed his clothes and headed for the door still nude. He didn't care. If the chairs with ropes still tied on them didn’t remind Bubblegum of her sexual submission to Finn then the reports of him walking out of the princess’s castle naked definitely would. Especially since he was still chewing on a piece of the hubba bubba herself.  



	3. Messing With The Undead...

**Summary for the Chapter:**

> Marceline, half demon half human hybrid and the queen of all vampires, is a being that you don't want to mess with. Well, you might not want too, but Finn enjoys a challenge and secretly Marceline is all talk and really no bite.

**Notes for the Chapter:**

> Hi everybody here on AO3!! 
> 
> I Hope everyone reading this story is having a wonderful Sunday evening!
> 
> Before we get to the story, I just wanted to take a moment and an extend a warm thank you to fellow A03 users, SomeGuy112 and MRJGSC for their kind feedback on the previous two chapters! 
> 
> I also wanted to thank all the readers who viewed my story in the last day or so! So far the story has 207 hits, 4 kudos and 2 bookmarks! Thank you all so much!!
> 
> Now without further delay, I present the third chapter of Experimental.
> 
> Happy reading!!

Word quickly spread about Finn’s odd nude stroll in The Candy Kingdom, much to Bubblegum’s embarrassment. Especially since the human had made it a priority to tell everyone that asked with the strange pink wad of bubblegum in his mouth, that he had just come from the princess’s room. He never said which room though. Just that he had been participating with Princess Bubblegum in a successful “experiment.” 

Marceline the vampire queen found the whole thing hilarious and extremely witty on Finn’s part. Not to mention kinky. The vampire didn’t need to know the fine details. She was well aware of Finn’s motives. After all both Bubblegum and Marceline had fucked his brains out a few weeks prior. Bubbles afterwards, had been worried that maybe they had been too rough with the hero, so worried in-fact that she had locked herself in her lab and devoted herself back to her science experiments. This was nothing new for Bubblegum. Isolating herself away from her loved ones to better understand the problem was one of the many common ways that the royal handled extreme stress. For Marceline though, Finn’s strange distant behavior towards Bubblegum in particular wasn’t a sign that the girls were too rough on him. It was a sign that they weren’t rough enough. 

Maybe that's why she had sought him out herself. Yeah, Marceline knew better. She was technically in a relationship with Bubblegum. But both girls had admitted that when Finn got to be of age that they had hoped that the blonde would join their sexual coupling. Adding benefits to their already strong friendship. So, it wasn't really an issue that the vampire helped Finn make his "vendetta" against the princess a reality. The princess had fantasied about similar things with Finn for awhile now. So, of course Marceline being the good girlfriend that she was would help Finn. No questions asked.

Of course, Finn had asked questions. Some she answered, others she brushed off with a wave of her hand. She had answered his questions about some of the kinks that Bubblegum had. For some reason the princess had a fetish for being stretched. Glob, only knew why. But his question like why Marceline was helping him fell on deaf ears. The queen had only answered his question with two of her own.

"Do you love Bubblegum like I do?"

He had thought about for only a second before blushing and nodded. 

“Do you feel the same way about me Finn?”

Sweet, gorgeous, naive Finn. He was wonderful. Marceline could tell that Finn wasn’t lying either when he once more quickly nodded. His face had turned such a delicious red. 

“Then, that’s all that matters.” The woman had answered that rainy night. 

The human male’s scent was so strange. Not bad. But strange. She had smelled the scent of lust on Finn right before she had collapsed on the ground after having sex with both Finn and Bubblegum. The vampire knew right then and there that the blonde may have orgasmed but he was nowhere near finished, that was still evident even weeks after the event.

But there was another feeling too that Finn was harboring. A scent that Marceline would compare to the delicate smell of freshly blooming flowers. It was a no brainer for the vampire. The scent while sometimes stronger at times than others, was love. It was something that she used to chalk up as just a silly little crush that the adolescent had. But then her feelings for Bonnie got stronger. She started smelling the scent not only Finn, but on herself as well. Bubblegum’s scent eventually started to smell similar, only fueling more of Marceline’s feelings, which in return made the sweet smell around Finn diminish slightly. The scent though never faded from the hero’s body completely. If anything the smell that lingered around Finn branched out towards two individuals as he got older. The scent still drifted towards the princess when the hero was around, but much to Marceline’s surprise, the smell also began drifting towards her as well.

It was only a year or so ago after Finn had nearly gotten absorbed by Gob that Bubblegum confessed to her girlfriend about her romantic feelings towards her hero. Instead of being angry, Marceline had long since come to the conclusion that her own flower scent of love, was not just for Bubblegum. But for the hero of Ooo too. Funny how things work. The duo knew that Finn felt the same way but neither of the ladies had the guts to actually ask the hero to confirm it. Well that was the case, until that rainy night a good few weeks prior.

The woman’s long fingers gently stroked the strings of her beloved instrument. Listening carefully to the notes that she was playing. Typical evening after a successful band session. The living area was a mess of papers, confetti, and assorted bottles of red juice. The queen paid little mind to the chaos. Her focus solely on returning her most beloved position and maybe a bit on the sexy male.

Finn was wonderful even when he was trying to be in control. The queen chuckled at the thought, especially In the end since Finn's own desire for sexual dominance made things work for Marcy’s own plan. Okay, maybe it wasn’t JUST Marceline’s plan. Both the girls had thought about and decided that they wanted to achieve the idea and Finn Mertens was their ideal candidate. So, while Bubblegum and Marceline may have created a sexual monster. One that neither of them had control over. It was all going to work out in the end. Hopefully.

The notes that her fingers created bounced around the living room. She strummed keys delicately just to hear the music as her mind continues to think about Finn. What was he up to now? Marceline had a pretty good idea. It wasn’t difficult to see that while Bubblegum might have been Finn’s main target, Finn’s desire for sexual gratification wasn’t just going to stop with her. Oh no. Marceline had a feeling that she was next on the human’s list. It didn’t scare her in the least. Bubblegum might not have shown to Finn that she enjoyed her “just desserts.” But Marceline was a different story. One could say that she was actually hoping that Finn would include her in his need for sexual gratification. She was more ready for her punishment. More than ready to see what the hero could do. 

In her trembling excitement the vampire plucked the C chord a little too hard. The string catching on her fingernail making the instrument release a loud almost tone deaf sound that made Marceline wince.

“Shit! That note I hit there was WAY out of tune.” She laughed out loud, looking down at the guitar in her hands. “Huh, some of the strings are loose. Guess I really was jamming tonight.”  
The woman laughed again, carefully tightening the small knobs at the top of the musical instrument.

A smile spread across her pale face as she tried the same notes again. This time the chords were perfect. She kept playing the notes, EM, G, C until her conscious mind recognized the song she was playing.

‘Hmmm, hmm, hmmm, hmmmm.” Her eyes closed in contentment only for them to open suddenly. A smile spread across her lips. 

“Sorry I'm not made of sugar.

Am I not sweet enough for you?

Is that why you always avoid me?”

It felt good to sing, even if Marceline’s choice of song was a bit dreary. Then again when the woman had written the song she was currently singing, her relationship with PB was rocky. There was no doubt that the woman had ever not loved Princess Bubblegum though. Even if, Bonnie especially back then just made Marceline want to scream.

“I must be such an inconvenience to you!”

Her voice bounced off the small walls that she resided in, as she let herself feel every word in her immortal being. Glob, the song was dark. The woman wondered why she even felt the need to continue singing it. Maybe because in some ways, Marceline still at times occasionally felt small when it came to the princess. Nothing like the dark feelings she once had for the candy monarch but there were still moments of jealous. Moments where Marceline would forget just how strange Bubblegum could be. How stupid peebles could be. Maybe that was another reason why she helped Finn. She understood how it felt to deal with the painful side of love.

“Well, I'm just your problem.

"I'm just your problem.”

The queen’s eyes narrowed at the sound of clapping behind her. Slow, mocking, clapping. Marceline didn’t need to turn around to know who it was. His musky lustful scent gave him away. 

Finn.

“S’up Marcy?” The blonde said. His voice was so deep that it reminded the vampire of velvet. The tone in the human’s voice made Marceline shudder. She still had her back towards him. 

“You left your window open, so I would just pop in and say hello.”

Damn Bubblegum! Leave it to Marceline’s feelings for her girlfriend to get her in trouble! Even so, Marceline couldn’t stop herself from turning to look at the man before her. Finn’s long blonde hair gently blew in the breeze. 

“Some hello.” She mouthed, smirking at the shirtless hunk before her.

Hungry eyes watched as Marceline drank in the sight of him. His muscular chest housed a nice 6 pack and a pretty decent tan. She could see all the way down to his hip bones. However while the view of the hero’s ripped form was quite intoxicating. It did not hold all of her interest. No, Marceline’s eyes were dead set on the big coil of rope that was loosely looped around and under one of Finn’s shoulders. The hero just smirked as he watched Marceline’s shocked expression.

“I know that you wrote that song about your past relationship with Bubblegum.” Finn whispered dangerously. The wind that came from the open window blew the dark curtains behind him ominously. 

“But you most definitely are my problem now Marceline.”

“You wouldn’t.” The queen started, backing up from the hero ever so slowly. Her eyes still gazing at the rope. Finn just watched her and smiled. 

“A problem that needs to be taken care of.” 

Marceline had no time to do much of anything before Finn pounced on the unsuspecting vampire. Pinning her arms quickly to the ground. The guitar dropping to the ground with a hard thud triggering a bunch of now once more out of tune sounds in the process.

“Damn Finn! I just got that tuned.” Marceline said annoyed. The hero just smiled at his captive. His long yellow hair tickling Marceline’s nose. 

“Well now you can tune up something else.” He winked before nibbling on Marceline’s pointed ears. 

She laughed against it all. Damn his cocky attitude. She didn’t resist when Finn gripped her chin, forcing her eyes to look at his. His blue eyes had a mischievous gleam in them.

“Really?!” Marceline rolled her eyes playfully. “I thought after finally fucking my girlfriend, you wouldn’t be so “strung” up on needing more sex.”

The human laughed obviously amused. His eyes finally looking down at himself, which sparked Marceline’s eyes to follow before resting on the massive bulge in the blonde’s pants.

‘You thought wrong.” The human lowly whispered before pulling a collar out of one of his short’s pockets. It was a simple black collar with an attached leash. 

Her eyebrows went up in confusion at the view of the collar. She was enjoying this little game. She had been expecting Finn, but she hadn’t been expecting him to be so, ummmm, what's the word? Dominating! Also Marceline definitely wasn’t expecting him to have that collar.

Finn laughed once more at the funny face that Marceline was making after figuring out the source of his friend’s puzzlement. “You thought I was going to use “this” first? Finn chuckled darkly. His eyes looking back and forth between the big coil of rope and the collared vampire underneath his strong body.

“Don’t worry though, we will be playing with the rope in a little bit.” The emphasis that Finn’s winking face made on the word playing, only caused the queen more aroused. The sound of the snaps closing the collar around her neck only made it worse. 

Finn slowly got off of her. The vampire subconsciously wondered if maybe it was because he could feel her wetness thru her tight jeans. She received the answer to her question shortly after.

“Stand up.” The human ordered his leashed comrade. Finn’s tone made Marceline shudder. It no longer held any ounce of humor. He was all business now. That in itself was incredibly sexy. 

Her slender figure arose under his watchful gaze. She really didn’t have much of a choice to refuse Finn’s command anyway. He literally had her on a leash. She was technically dead, yes, but that didn’t mean that she couldn’t feel pain from having something constricting her throat.

“You are my “henchman” for the evening Marceline. You will refer to me as "sir" whatever I ask you will do, no questions asked." The cold blue eyes seemed to stare right thru Marceline. “With that collar on your vampire powers are completely useless. You can thank your girlfriend for leaving that collar out on of the tables in her lab. Because now Marceline you are completely at my mercy.”

“Understand?”

The vampire nodded trying to keep the excited sarcasm out of her voice. How the hell did Finn find the slave collar? Marceline had been looking everywhere for the damn thing. Guess Bubbles was a sneaky little crook after all, to sneak it out of Marceline’s bedroom without the immortal even knowing.

“Yes, sir.”

“Come.” The human demanded, forcing the queen to walk straight. The leash in Finn’s hand was gripped tighter as he led her towards the red ladder.

One of her captor’s strong hands held itself out for a moment. A simple indication that he wanted her to climb up first. Marceline stared at the ladder and then back at Finn, who was standing behind her waiting for her to move. 

‘There should be enough slack to climb, per-say.’ She thought. ‘Should be more than easy.’

Honestly though Marceline couldn’t remember the last time she had climbed the ladder. The steps most certainly were old and under closer inspection needed a newer layer of red paint. Not to mention that the splintered steps looked like they could barely contain one of her small feet, let alone her whole body if she stepped on one. How the hell had Bonnie used it all these years?

If only the woman could fly like all the other countless times. Or better yet, use some of her other vampiric powers. However, Marceline was currently leashed like an animal, thanks to her kinky ass girlfriend’s invention. Every time the queen attempted to use ANY of her powers the result ended the same. Absolutely nothing happening. Marceline was pretty much just like a human. No powers and no escape from her fate. That being said, the only thing that Marceline could do was to climb the ladder. Even if it was a little strange and maybe a bit unsafe.

“Climb.” 

The immortal said nothing as she felt Finn gives her a gentle yet firm push. The ladder creaked as she carefully climbed. Finn’s footsteps echoed behind her until she finally reached the wooden flooring of her bedroom. Marceline dared not move until Finn himself was on the creaky upstairs floorboards with her.

He walked around her, leash still tightly contained in his hand, until his eyes came across a strange hook sticking out from the ceiling posts. Finn inwardly laughed, it didn’t take a genius to put two and two together to figure out what that thing was used for. It was well known by Finn Mertens that the fair skinned woman was into kinky shit.

As a young boy, Finn had on numerous occasions snuck into the vampire’s home. That hook was used for suspending a naked, bound body. The last one being Princess Bubblegum herself. A flush spread to his pale cheeks at the memory of the last time he saw the two having sex.

The rope that had caught Marceline’s attention earlier was thrown into the air and landed neatly over the rustic hook. Finn pulled on the rope tightly almost as if he was testing the hook’s strength. After a few moments of silence, The blonde turned once more to Marceline. 

“Come here and give me your hands.”

“Yes sir.” 

Marceline’s slender wrists were wrapped once, then twice in the rope. Then Finn brought the rope in between her delicate wrists a few times. Only stopping when the hero ran out of his end of the rope. With her hands bound in front of her Marceline found herself enjoying the feeling of helplessness that was starting to overtake her. She would question Finn later about how he knew about the bedroom hook’s actual purpose.

“You’ve been a bad girl Marceline.” Her captor taunted, the leash was still wrapped around his hand as he watched his prisoner with a new level of lust. The musky scent was just covering all of Finn’s other senses. It was sexy to smell how much the human wanted Marceline.

“A very bad girl indeed.” 

Finn’s hand traced her body. She was smaller breasted than Bubblegum, maybe a c cup, but she definitely made up for it in her hips. They were big, as was her luscious bottom. Finn had always been more of an ass man. He just stemmed it up from all the ladies he had carried bridal styled over the previous years as a hero. A savior doesn’t get as close to a woman’s breasts when he’s carrying a gorgeous damsel. 

Marceline’s body was warm, flushed one might even say as Finn stroked her gray skin. He was being so gentle that it was becoming torture for the wild hardcore kink machine. She was about ready to whine when Finn’s hand grabbed the loose rope and pulled. Marceline’s arms were forced tightly above her. Her feet just barely touched the cold, wooden floor. The queen had no choice but to accept that her arms were out of the question when Finn tied the loose end off. Again Marceline questioned how he knew so much about her room.

“You need to be punished.”

Now this was what she was talking about. She closed her eyes in anticipation. Only for nothing to happen. The hell?

Her eyes opened to see Finn looking through her closet, Marceline squirmed in her restraints now that her collar wasn’t constricting her throat. What was he doing?

“Ahhh, found it.” Finn said amused. His back was still towards the extremely embarrassed vampire. Marceline could still smell the scent of lust when on her captor, but now she found herself also smelling a strong scent of excitement radiating off of the blonde. Marceline’s nose was indeed right, Finn Mertens was most certainly excited. The excitement only intensifying when the blonde pulled out a small chest. The lid opened with a loud and shrill creak. 

‘Oh Glob. He had found it.’ Marceline’s panicked brain thought. ‘Oh shit!!’

“Thought so.” He smirked, laughing at Marceline’s appalled reaction. His hand dumped the box’s contents on the bed. Some smooth, silky rope, some lubricant, a roll of duct tape, a whip, and the vampire’s own boyfriend, a pink vibrator. Finn smiled, breathing in the sweet smell that the sex toy was emitting.

“I know that sweet scent anywhere.” The human purred. “This is you and Bubble’s own personal stash.”

Marceline tried to kick but Finn only turned and held her legs together, tracing the vibrator up and down her hips. “You dirty, naughty thing.” He scolded playfully. “You have used this on PB, haven’t you?

The queen let out a sigh when she felt Finn mess with her pants. They slowly slide down to her ankles and then fell to the floor. “You truly are a wicked thing.” 

Finn’s mouth found its way to the thong that covered the Vampire's womanhood, kissing her lacy cum soaked panties passionately. His teeth quickly found one of the corners and pulled them gently down, exposing the queen’s womanhood.

“Oh Marceline.” The hero sighed, his fingers playing with her folds. Glob she was beautiful. Completely gorgeous. Finn pressed and traced Marcy’s vagina easily. Unlike Bubblegum she was completely giving up her control. 

Speaking of control.

Marceline’s eyes widened when she felt the familiar feeling of the medal boyfriend in her entrance. Finn just smirked deviously as the vibrator turned on with a start. She was already so close that the vibrator just being on almost sent her over. She was ready. So ready. Then it stopped. 

Finn smiled as Marcy glared. The control button fit perfectly in the human’s pocket, much to Marceline’s growing frustration. With both his hands free, tearing the last little bit of clothing that Marceline was wearing was easy. The woman was no doubt enjoying this but still couldn’t help but get annoyed when she watched the two halves of her beloved shirt fell to the ground. 

“Fuck Finn! That was my favorite shirt.” The woman pouted. Her full red lips even showed a little bit of her fangs as she found herself smirking. Finn just circled her again. Marceline tried to follow him but was unable keep up with his movement. She could feel his sweet breath on her neck as his hands grabbed her breasts from behind. Damn! If she had known that Finn was planning on doing this today, she would have forced her lazy ass to put on a bra. Damn her luck!!

“You don’t make the rules here Marceline.” The blonde said softly, enjoying the way that the beauty arched into him. “I do.”

CRACK.

Sharp tingling radiates across her now bareback. The woman squealed as the sensation burned. Her toes curled as she shuddered at the pleasurable pain. The vibrator turned on briefly, Marceline screamed out as she felt her own body build.

“Oh Glob!” 

“Oh Glob!”

“Oh GLLLOOOO……..Seriously?! What the fuck Finn?” The vampire roared. “Is this the shit you pulled with Bubblegum!!??”

Marceline could sense that Finn was smirking. Damn him! He was good! 

“I told you, I make the rules here. Not you.”

Finn’s fingers were in Marcy hair, pulling her head back roughly. The woman sighed.

“But no, if you must know the so called shit I pulled with Bubblegum was much more tortuous.”

She was about ready to ask Finn how, when another sting fell across her bare back. Marcy screamed out as the whip collided with her body. Finn’s hand was still clutching the hair close to her scalp as she twisted under Finn’s hold. Marceline’s whip, that she had used on Bubblegum a few weeks prior, while they planned out Finn’s birthday surprise was now the source of the vampire’s immense pain and incredible pleasure. The woman counted 3 more lashes before the vibrator clicked back on.

Finn walked back around to face his moaning hostage. Her back had more than enough of the whip’s kisses. It was the vampire’s lips turn. The pretty lady’s eyes were closed as she squirmed in her restraints. The hero kissed her parted lips, pleased when the woman kissed him right back. Their moist tongues met causing both individuals to moan together. 

The kisses grew more faster. A symbol of both partners growing desire. As the make out session grew heavier, Marceline’s long legs desperately tried to wrap around the human’s waist. Her wet essence touched Finn’s own member as her attempts to get closer to his own aroused body finally became successful. The pleasure between the hungry kisses, Marceline’s humping and the simple fact that the said woman was tied up before him almost caused him to lose control.

Almost. 

Finn pulled away, clicking the vibrator off as he did so. Marceline’s legs fell quickly back to their original position above the floor as she whimpered at the loss of needed sexual contact.

“Oh Glob Finn! Let me climax! Please!” She said out loud. 

“It hurts doesn’t it?”

Marceline just looked at him in wonder.

“For so many years, I have been feeling what you are currently feeling.” 

Finn’s hands were caressing her body again, his mind focused on the woman’s pale figure.

“Wanting to feel.” A strand of black hair blew in Marceline’s face. Finn gently put it behind one of the woman’s pointed ears.

‘Wanting to move. Needing to release.”

The hero pinched her leaking walls sadistically before wrapping his arms around her chest.

“Since I was 12. Since I first met you and Bubblegum, I have been harboring these feelings.” The blue eyes looked at the vampire. They were about as dark as Marceline’s hair.  
“I tried so hard to push them aside. To be a hero. But now, I don’t have to hide these dark feelings.” 

Finn pushed her away roughly. The vampire swayed in reaction to the human’s movement. For the briefest of moments Marceline was happy that her arms were keeping her still. Without her arms tethered high above her, the queen most certainly would have lost her balance.

“You and Bubblegum made me realize that I don't have to be a hero when it comes to the bedroom.” 

The whip that Finn was holding loosely, suddenly lashed out kissing Marceline’s breasts. The said woman screamed at the response.

“I can be the villain and I like that better.” 

Marceline shuddered as the vibrator kicked back on as Finn continued. His words were making the vampire shudder more than the stinging on her boobs.

“I am going to make you feel my frustrations Marcy.” 

Crack.

“Every…”

CRACK

“single…”

CRACK

“...one.”

Scars lined her erect breasts. Her slender chest housed numerous deep wounds. The woman panted, her body once more edging closer and closer to orgasm. Finn taking off of his shorts and exposing his enlarged member only added to the immortal’s intense need for sex. Marceline was well aware of Finn’s size. Well, she thought she was. 

Glob! That was Finn?! Holy crap!! Marceline didn’t remember the human being that big! Was he holding back when the girls had him at their mercy? Shit! If she would have known that Finn was that big, Marceline would have done more than just accept Finn’s invite to that shitty romance movie those many years ago. Shit! They would have gone back to her place and Finn would have gotten a front row seat at one of Marceline’s own “shows.” 

“Like what you see?” Finn asked winking. Marceline couldn’t even nod. Nor could she resist when Finn walked behind her sore body again. 

“Happy to see that you approve Marcy, because this is the last thing you ever will gaze upon.”

The electronic boyfriend buzzed in her vagina as The human pulled the leather strap tightly that attached to her collar. It tightened around Marceline’s neck instantaneously. She thrashed her head fully trapped in her peril. Finn’s deathly grip never let go of his hold though. If anything Finn extremely aroused with his submissive’s lack of control grew even more in length.

“Oh Marceline.” 

“Ooohhh Marcy.” He panted and huffed. His member was leaking in its own excitement. The human moaned out loud as he humped her backside.

Drool started to fall down her chin as he played with her spasming figure. The vampire’s feet danced, her toes curling and uncurling as Marceline accepted her helplessness. It hurt what Finn was doing, but Glob it was fucking kinky. It was almost like Finn knew that Marceline had a strangulation fetish. But that was impossible, right? Bubblegum didn’t even know that Marceline pretended to hang herself when she wasn’t over. So, Finn couldn’t have known the true depths of Marceline’s arousal. Right?

The vampire’s tongue perturbed from her mouth as she felt Finn in her anus. He pumped deeply into her hard, screaming her name as he did so. The vibrator buzzed harder. Glob she was close and from what she could feel so was Finn. Her brain struggled to process what Finn was doing.

Marceline’s ass was tight, yet warm. The human could feel the walls around his dick, similar to if he was in a woman’s vaginal entrance. Just like the vagina, the backdoor entrance squeezed gently around his own genitalia. It felt good. Really good. Interestingly enough, Finn could also feel Marcy’s own inner excitement. Even from the outside end, the hero could feel the buzzing sensation that was enclosed in the queen’s other entrance.

“Come on Marceline.” Finn shouted. His warmth was merging with hers. “Cum for me. Cum for the one that owns you!”

The queen was dizzy and light headed from the pain around her throat. Yet she heard Finn’s request. Never had anyone claimed that they owned her. Not her father, not Ash, not even Bubblegum her own girlfriend had the balls to say such a thing. 

It was the most sexiest thing that she had ever heard. Finn screamed out just as the vibrator finally sent Marceline over the edge. She could feel Finn’s cum as it ejaculated into her anus, causing her to shudder even more violently during her own orgasm. The human’s hand released the leash, as he stumbled backwards obviously still feeling his own climax. He fumbled with the ropes with the full intent to release the submissive from her bondage.

“No…..please don’t...sir ...please.”

Finn panted. His body was so tired. Satisfied but tired. Yet even so Finn somehow found the energy to face Marceline face to face. Her long black hair covered her face. He watched as the some of the strands blew in her breath. That was to be accepted. What Finn wasn’t expecting was the woman to gaze up at him with such a look.

“Please sir. I need more.” 

Her eyes were slits as she looked at him. Begging hungrily for Finn’s dominance and more of his own brand of sexual torture. 

“I haven’t been punished enough.” 

He smirked, his own cum coated member hardening once more as she licked her lips while staring at the beautiful human before her. 

“I need to be reminded more of who owns me.”

“And who owns you Marceline?” He questioned, fully reverting back into his dominating role. 

“You.”

The calloused hands reached up to hold Marceline's flushed cheeks passionately as Finn's lips once more found the more than ready submissive's.

Who was he to refuse such a lady?


	4. Open

**Summary for the Chapter:**

> Sometimes watching a romantic movie with the ones you love really makes a person think of have lucky they really are. Even if Finn spent a good portion of it in a very undignified position. Marceline and Bubblegum really do take our blonde hero's breath away....

**Notes for the Chapter:**

> Hello again all my readers!!
> 
> I want to extend a special thank you to everyone who given me kudos, wonderful feedback and bookmarked this writing! 
> 
> I also want to thank everyone who just taken the time to read what I have written. This story so far has achieved so much more attention than what I would have thought possible! THANK YOU ALL!
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> Now, enjoy reading the final installment of Experimental and as always, I wish you very happy readings!!

Funny how things work out.

Finn once again found himself in a tight predicament. Red nylon rope covered his wrists elbows and chests, forcing his strong arms in a prayer like position that at least allowed his hands to rest gently overtop his boner. Finn’s arousal at least helped with the aching pain in the human’s legs. He was sitting on top of them and due to the tight ropes wrapped around his thighs, knees and ankles, he was pretty much immobile.  
Still though, Finn did attempt to twist and turn. Consider it a force of habit.

Honestly though the only real difference with his bondage other than the positioning and the fact that this time, there was a pair of sickeningly sweet panties that were balled up in his mouth, was the strange sack that Finn found himself packaged in. Finn had tried a few times to spit out the thick wad that was his gag, but like with everything else only ended up getting himself more frustrated. 

Finn was tied up, gagged and in some sort of bag, clothed only in his boxers. But the scariest, and if Finn was honest kinkiest thought was the simple fact that if the hero wasn’t careful then he could very easily suffocate. Then again, the hero knew that his captors would let too much pain befall him. 

“Hey! Thanks for pausing! I popped the last bag of popcorn.” 

Finn listened carefully to the cheerful tone of the princess. Bubblegum really shouldn’t be doing so much physical activity. Not in her current state anyway. Even going up and down the steps to make a bag of popcorn could be dangerous. But Finn also knew that no one could stop the princess when she got it in her head that she wanted to do something.

“Yeah sure bubbles, even if we have watched this movie like fifty times.” Her girlfriend, Marceline answered. Finn would almost say that vampire sounded bored. “You really shouldn’t be moving around so much.” 

The notes that Marceline the vampire queen were playing stopped abruptly yet no footsteps were heard. Indicating to Finn that the woman had floated over to Bubblegum.

“I know. I know Marcy. I just am so stir crazy.”

“I know bubbles, trust me I do, but right now your safety comes first. Remember, It’s not just about you anymore.”

“Do you agree with me Finn?” The vampire questioned, her eyes gazing at the bound, trussed up figure of the blonde in the corner. He struggled a bit in his ropes from what Marceline could see, but other than that did nothing else. The sack that the human was currently tied up in grew even more silent as both of the women’s footsteps walked by.

“He can breathe in there, can’t he?” Bubblegum whispered when the girls got close to the bed. Marceline helped Bubblegum’s bottom gracefully collided with the vampire's top quilt. The popcorn bowl tilted a bit at the impact, sending a few red dyed popcorn pieces onto the bed. The black haired beauty only kept her eyes on her girlfriend as allowed herself to sprawl out beside the candy.

“He’s fine PB. This is exactly what he deserves.”

Bubblegum chuckled softly. One of her small hands gently resting on her protruding belly as she smiled. “Yes, I suppose you are right Marcy.”

“After all the trouble he’s caused us that’s the least we can do him.” 

Finn moved again at the response causing the brown bag to make a few crinkling noises. Both of the women just laughed at the hero’s struggles. Especially when Marceline sat up and threw a piece of popcorn at Finn’s body. He thrashed a bit and made some sort of moan before falling onto his side. The royals could see his hands flex in their prayer like position if they looked hard enough. It was extremely sexy watching the way their prisoner squirmed in his bondage. Almost sexy enough to let the blonde out of his containment.

It was a tempting thought, but still the queen grabbed the remote and re-started the aged movie. It was by far Bubblegum’s favorite. The movie they were watching was created way before the vampire’s own time. Yet Marceline’s own fondness for the film was due to the memories of watching The Princess Bride with her mother. Such nice memories.

Bubblegum’s hand rested on Marceline’s momentarily before the two kissed passionately. The only lights in the room were coming from the tv, dimming the two lovers as they continued their kissing. Finn rolled a bit on the wooden floorboards, obviously aware of the make out session that he couldn’t see. The hero said something muffled, causing both girls to glance Finn’s way.

“Let’s let him out Marceline.” Bubblegum whispered. Her mouth gently nibbling on her lover’s ear. “He’s been in there for awhile now.” 

Marceline only sighed as Bubblegum stood up. The vampire’s hands gently gripped the candy’s waist before pulling her back down on the bed. The action almost knocking the bowl of popcorn beside Marceline to spill its contents all over the bed.

“Here, hold the popcorn. I will go get Finn.”

Finn had just started frantically doing a sliding motion with his hands, when Marceline’s hands found their way underneath the human’s squirming figure. He thrashed against the vampire’s hold, desperately trying to reestablish the momentum that his fingers were previously achieving. He had run out of air. If he was going to die, he might as well get there one last time. Though the queen’s hold on him wasn’t making his last wish easy to carry out.

“Jeez Finn! Stop squirming.” Marceline warned. It wasn’t easy in general carrying Finn in her arms while floating back over to Bubblegum, this was especially the case when the said hero was struggling profusely. “Do you want me to drop you?!” Bubblegum only giggled at Marceline’s frustrated yell. Even tied up, Finn Mertens was still a challenge.

Finn felt Marceline’s fingers loosening right before he found himself falling on the bed with a soft thud. He was just starting to see stars when the candy monarch started to untie the bag’s strings. Soon he felt the bag slide down past his head until it stopped right at the hero’s shoulders. Well, at least he could breathe. For that Finn was grateful, he happily exhaled and inhaled deep breaths of the refreshing oxygen that he was granted access to.

“There, is that better?” the candy asked, stroking the blonde’s soft cheek. Their eyes met as Marceline hands started untying the panty gag.

“Yeah.” The hero whispered when the gag was removed. His blue eyes quickly darting back down to Bubblegum’s stomach.

“Looking at your handiwork Finn?”

Bubblegum couldn’t help but smile as she watched Finn’s quickly nod. She chuckled and Marceline followed.

“I gotta say I wasn’t expecting that kind of sexual kinkiness from you.”  
Finn opened his mouth to tell Bubblegum that he had some help, but promptly closed it when the princess raised her hand. Marceline snickered at Finn’s expression.

“But I enjoyed every second of it and I know that Marcy here, did too.”  
The vampire just shrugged, her mind more focused on the princess and the pirate in the movie. “Yeah, yeah whatever.” A small smile though did tug at the vampire’s lips.

“But by far the best part is this.”  
Bubblegum’s fingers traced her enlarged stomach momentarily.

“With my immense genius, I could have created life using chemicals, myself and Marceline’s genetics. It would have been easy, I mean I have done it before. But something about being pregnant with not only a child that has genetics from Marceline and myself, but also traits from you Finn, is beyond comparison. It’s something that I have always dreamed about achieving.”

Bubblegum’s hands found their way in Finn’s blonde hair. The human closed his eyes in contentment, enjoying the sensation that the princess was creating. He didn’t resist when her long dainty figures pulled him, forcing his bound body to fall between the two girls.

“That doesn't look comfortable dude.” Marceline laughed, looking at the hero whose hair was tickling a good portion of her right arm. Finn just gave a tired sigh as Marcy turned slightly and helped the hero free himself completely from the sack’s hold. From Marceline’s seated position, she could see the man’s erect dick. She would have to take care of that later. The vampire’s cold fingers quickly got to work at unfastening the ropes that were holding Finn’s lower half hostage. With his new sense of freedom finally achieved the man stretched his long legs out, gazing at the two loving figures beside him.

Yeah, Finn was mad at first when the vampire had come clean about the girl’s plan. He had originally felt manipulated about the whole ordeal, especially after Marceline told him that she had given Bubblegum a heads up a half hour before about Finn’s plan. The hero had stormed out of the vampire’s bedroom in anger. It didn’t help that Marcy had shouted out that she had only reached out to Bubblegum so that the woman could pour a vial on her groins that contained the queen’s own genetic materials, so that the baby would have traits from all 3 of its parents. Finn felt betrayed and worse of all fearful. What would Bubblegum say? Would she agree with Marceline’s story or would she just scold and make Finn feel insignificant like always?

However Finn was wrong about Bubblegum scolding him. It took some time but when peebles finally did open up to him she was ecstatic. The hero wasn’t quite sure how to take the princess’s emotion when both of the females had unexpectedly dropped by Finn and Jake’s treehouse. Thank Glob, Jake was out with Lady. Bubblegum wasn’t even in the doorway before she started happily explaining the potions that she had taken. 

The one was almost like a lubricant which she had carefully smeared all around her womanhood. This cream like substance though was entirely the vampire’s material, just like Marceline had said a week or so earlier. What the vampire hadn’t shared was how difficult it was for Bonnie to get the needed specimen. Bubblegum had gone on and on talking about having to literally tackle Marcy down on the ground to get a piece of her hair to begin the process. Finn had already been conflicted. But then the princess started exclaiming the other potion that she had used to hopefully delay her own body’s defense system so that her gum wouldn’t contaminate the precious liquid on her folds. Finn’s confusion only intensified after hearing that part.

Why wouldn’t Marceline and Bubblegum have just asked him for his sperm? He would have said yes without hesitation. Then there wouldn’t have been a need for time delaying vials or the feeling of immense self pity that the hero had felt at both the female’s confession. He felt like he was drowning as Bubblegum kept talking about how successful the experiment went. How excited she was to finally be able to have their baby grow inside of her.

Finn was looking for a way to escape the two royals that were cornering him in his very own kitchen, when Marceline had reminded him that the baby inside Bubblegum was his too.That statement had relaxed and flattered Finn, but not as much as the emotional response he had received from peebles directly after.

“We want you in the little’s one life. You are the baby’s father after all.”

Those words opened Finn’s eyes, because the more the man thought about the child and his two best friends, the more he realized that the love he felt for the two extended far past what he had originally thought. Finn honestly loved Marceline and Bubblegum with all of his very being and being able to have the opportunity to create life with them was something that only deepened his already strong feelings.

It had been a month since Bubblegum had said that. A month since Finn had been included in the two royal’s weekly movie nights. A month since the hero had decided that he wanted to be a part of the two lover’s relationship and a month since he had come to the conclusion that he wanted to be a father figure to the unborn child that all three of them shared genetically.

With that notion, It had so far been the happiest month of Finn’s life. Marceline’s desire for sexual stimulation went thru the roof, but also was her almost obsessive fascination with once more writing current music. Oddly enough the songs that Marcy wrote no longer sounded as desperate or lonely. They had a very meaningful lyrics that no longer held such saddening inner darkness. It was beautiful to hear how far the vampire had come from just a few years ago.

As for the princess, even if she couldn’t really participate in sex with Finn and Marceline, she made up for it with her constant strange need for affection and physical touch. The candy was super emotional as well. Finn actually found it endearing, how many times Bubbles complimented him. Even when it was his turn to be submissive, Bubblegum still found a way to make him feel appreciated. 

Screams started coming from the tv screen, indicating the start of the infamous torture scene of the princess’s lover. Finn had seen this movie before. It was last week’s movie choice as well and if Finn recalled correctly, the week before that as well. Yet, for the first time Finn didn’t jump when the screams intensified. He didn’t need to be a hero at the current moment. His blue eyes were too focused on the loving women all around him that had saved him.

Finn’s lips gently kissed Bubblegum’s stomach, noticing quickly the smiles of both Bubblegum and Marceline. Marceline sighed before snaking an arm around Finn’s shoulders, she left a quick kiss on his one cheek before returning to the movie. Bubblegum if possible snuggled closer to Finn, copying her girlfriend’s move and placing a small kiss on his cheek.

He had no idea how to be a good father figure, but he would figure it out. The only thing Finn still hadn’t figured out is why PB’s need to conduct a so called experiment was even needed in the first place? It was very obvious from day one Finn’s feelings. But who was he to question Princess Bubblegum's “genius?" Who was he to question any of the happiness that he had finally been granted?

**Author's Note:**

> Adventure Time may be owned by Pendleton Ward, but the idea for “Experimental” is my own. So, thank you guys so much for supporting my writing and reading!
> 
> If you liked what you read, please remember to COMMENT, KUDO, and/or BOOKMARK!! Your feedback is greatly appreciated!
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> THANKS AGAIN!!


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